Latches used on tailgate doors (described as the rear gate door) are hinged at the top and close downwardly and shut against a pickup tailgate, on a pickup "topper", or other equivalent "RV" application, and are of two common types: double T-handle and single T-handle with lock-rods.
The double T-handle is two T-handles, one affixed to each side of the door's lower edges, and each provided with a latch blade that engages against a beveled latch plate affixed to the door frame. Rotating the T-handles approximately 90 degrees pulls the door shut against the door frame and weather seals the door, securing the door in its closed position.
The single T-handle with two lock rods is a single T-handle mounted at the bottom center of the door, provided with a rotor assembly. The two lock-rods are connected to the rotor and extend out to each side, through a rod guide adjacent to the door edge. Again, a beveled latch plate is provided on the door frame at each side.
Rotating the single center T-handle approximately 90 degrees then extends the lock-rods outwardly, both right and left, engaging rods against the latch plates and securing the door in a closed position against the door frame, and weather sealing the door frame.
Security: Because of their design, a locked door can be breached by simply spreading the lower corners of the cap, or by applying enough force at the handle to bend and/or distort the lock-rods or their guides.
Because toppers are of reasonable lightweight construction, when handled during manufacture, shipping, or storage, they tend to lose their fit and dimension at the lower rear portion. This is due to spreading or bending of the sides, thus affecting quality and/or requiring extra handling care and expense, etc. Also, spreading of the sides of the topper is caused, during use, due to vehicle vibration and general wear nd tear.